.\"
.\" @(#)pg.1	1.18 (gritter) 1/24/05
.TH PG 1 "1/24/05" "Heirloom Toolchest" "User Commands"
.SH NAME
pg \- file perusal filter for CRTs
.SH SYNOPSIS
.HP
.ad l
\fBpg\fR [\fB\-\fInumber\fR] [\fB\-p\fI\ string\fR]
[\fB\-cefnrs\fR] [\fB+\fIline\fR] [\fB+/\fIpattern\fB/\fR]
[\fIfile\fR\ .\ .\ .]
.br
.ad b
.SH DESCRIPTION
.I Pg
displays a text file on a
.SM CRT
one screenful at once.
After each page, a prompt is displayed. The user may then either press the
newline key to view the next page or one of the keys described below.
.PP
If no filename is given on the command line,
.I pg
reads from standard input.
If the standard output is not a terminal,
.I pg
acts like
.IR cat (1)
but precedes each file with its name if there is more than one.
.PP
If input comes from a pipe,
.I pg
stores the data in a buffer file while reading
to make navigation possible.
.PP
.I Pg
accepts the following options:
.TP
.BI \- number
The number of lines per page. Usually, this is the number of
.SM CRT
lines
minus one.
.TP
.B \-c
Clear the screen before a page is displayed
if the terminfo entry for the terminal provides this capability.
.TP
.B \-e
.I pg
will not pause and display 
.SM (EOF)
at the end of a file.
.TP
.B \-f
.I pg
does not split long lines.
.TP
.B \-n
Without this option, commands must be terminated by a newline character. With
this option,
.I pg
advances once a command letter is entered.
.TP
.BI \-p \ string
Instead of the prompt
.I " :"
,
.I string
is displayed.
If
.I string
contains
.I %d
, its first occurrence is replaced by the number of the current page.
.TP
.B \-r
Disallow the shell escape.
.TP
.B \-s
Print messages in
.I standout
mode
if the terminfo entry for the terminal provides this capability.
.TP
.BI + number
Start at the given line.
.TP
.BI +/ pattern /
Start at the line containing the regular expression
.I pattern
given.
.PP
The following commands may be entered at the prompt. Commands preceded by
.I i
in this document accept a number as argument, positive or negative.
If this argument starts with
.I +
or
.I \-,
it is interpreted relative to the current position in the input file,
otherwise relative to the beginning.
.TP
.IB i <newline>
Display the next or the indicated page.
.TP
\fIi\fR\fBd\fR or \fB^D\fR
Display the next halfpage. If
.I i
is given, it is always interpreted relative to the current position.
.TP
.IB i l
Display the next or the indicated line.
.TP
.IB i f
Skip a page forward.
.I i
must be a positive number and is always interpreted relative
to the current position.
.TP
\fIi\fR\fBw\fR or \fIi\fR\fBz\fR
Behave as
.I <newline>
except that 
.I i
becomes the new page size.
.TP
.BR . " or " ^L
Redraw the screen.
.TP
.B $
Advance to the last line of the input file.
.TP
.IB i / pattern /
Search forward until the first or the \fIi\fR-th
occurrence of the regular expression 
.I pattern
is found. The search starts
after the current page and stops at the end of the file. No wrap-around is
performed.
.I i
must be a positive number.
.TP
\fIi\fR\fB?\fR\fIpattern\fR\fB?\fR or \fIi\fR\fB^\fR\fIpattern\fR\fB^\fR
Search backward until the first or the \fIi\fR-th
occurrence of the regular expression
.I pattern
is found. The search starts
before the current page and stops at the beginning of the file.
No wrap-around is performed. 
.I i
must be a positive number.
.PP
The search commands accept an added letter. If
.B t
is given, the line containing the pattern is displayed at the top of the
screen, which is the default.
.B m
selects the middle and
.B b
the bottom of the screen.
The selected position is used in following searches, too.
.TP
.IB i n
Advance to the next file or
.I i
files forward.
.TP
.IB i p
Reread the previous file or
.I i
files backward.
.TP
.BI s \ filename
Save the current file to the given
.I filename.
.TP
.B h
Display a command summary.
.TP
.BI ! command
Execute
.I command
using the shell.
.TP
.BR q " or " Q
Quit.
.PP
If the user presses the interrupt or quit key while
.I pg
reads from the
input file or writes on the terminal,
.I pg
will immediately display the prompt.
In all other situations these keys will terminate
.I pg.
.PP
.I Pg
uses limited regular expressions as described in
.IR ed (1).
.B /usr/5bin/pg
uses simple regular expressions,
.BR /usr/5bin/s42/pg ,
.BR /usr/5bin/posix/pg ,
and
.B /usr/5bin/posix2001/pg
use basic regular expressions.
.SH "ENVIRONMENT VARIABLES"
The following environment variables
affect the behavior of
.I pg:
.TP
.B COLUMNS
Overrides the system-supplied number of columns if set.
.TP
.BR LANG ", " LC_ALL
See
.IR locale (7).
.TP
.B LC_COLLATE
Affects the collation order for range expressions,
equivalence classes, and collation symbols
in basic regular expressions.
.TP
.B LC_CTYPE
Determines the mapping of bytes to characters,
whether a character is printable,
and the availability and composition of character classes
in basic regular expressions.
.\".TP
.\".B LC_MESSAGES
.\"Sets the language used for diagnostic and informational messages.
.TP
.B LINES
Overrides the system-supplied number of lines if set.
.\".TP
.\".B NLSPATH
.\"See
.\".IR catopen (3).
.TP
.B SHELL
Used by the
.B !\&
command.
.TP
.B TERM
Determines the terminal type.
.SH "SEE ALSO"
cat(1),
ed(1),
more(1),
sh(1),
terminfo(5),
locale(7),
regex(7),
term(7)
.SH NOTES
.I Pg
expects the terminal tabulators to set on eight positions.
.PP
.I Pg
contains limited support for terminal escape sequences
in its input,
e.\|g. it is possible to view text in color and boldface as with
``lc\ |\ pg''.
Sequences that affect more than one output line
are not supported, though.